About 4h30. There are 5-6 trains per day.
Take a train from St Moritz to Chur. At Chur change for a train to Zurich. At Zurich Hauptbahnhof take a train to the Paris Gare de l'Est.
By train, it will take 8 hrs 20 minutes.
For a train journey from Milan to Zurich it would take approximately four hours to get one way.
Better to take the train. 10-15 minutes by train.
According to raileurope.com a train from Paris to Madrid takes approximately 13 hours.
About 4 Hours.
clear 3 hours
About 10-15 minutes by train from Zürich Hauptbahnhof (Main station) to Zürich Flughafen (airport). A lot longer by car.
The quickest train from Brussels to Paris usually takes not very long at all. The quickest train from Brussels to Paris usually takes about one hour and fifteen minutes.
7 to 8 hours.
About 3 hours
1 hour